For climate's sake, let's cut food waste!

At least a third of the food the world grows each year goes to waste, writes John Mandyck, most of it in fields, transport and storage. The result is poor farmers, hungry people, and a massive 3.3 billion tonnes of needless CO2 emissions. It should be a key topic for action at COP21 in Paris - but so far it's not even on the agenda.

If we measured food waste as a country, it would be the third largest emitter of greenhouse gases behind the China and the US. This is stunning, especially when you consider that one in nine people don't have enough to eat.

Reducing food waste is the only climate action that reduces greenhouse gas emissions while unlocking solutions for hunger, nutrition, water scarcity, economic expansion and national security. No other can do the same.

Yet the connection between food waste and climate change is missing from policy discussions and public discourse. Most notably, food waste has a muted presence on the COP21 agenda. It should be front and center.

The global population is forecast to reach 9.5 billion by 2050. At our current rate of growth forecasters believe the Earth must support an increase of 60% to 120% in global crop demands. It doesn't make sense to continue with the current paradigm, which is to grow more - and throw more away - to try to feed more people.

Farming is already responsible for 14% of global greenhouse gases and significantly impacts our natural resources: 38% of our ice-free land is currently used for farming (compared to just 2% for all cities on the planet) and 70% of all our fresh water is used to grow food.

We already produce enough food to feed 10 billion people. The problem is that one-third or more of all food produced is lost or wasted. Two thirds of food loss occurs before it reaches the consumer. It rots in the fields post-harvest or in poor transportation systems to markets and consumers. This is particularly prevalent in developing economies.

Food waste in Asia - a case study

With its huge population and relatively undeveloped temperature-controlled supply chain (known as the cold chain), Asia's food loss happens across the continent. According the the FAO's Food Wastage Report, Industrialized Asia absorbs 28% of global food loss and South and Southeast Asia 22%, accounting for 50% of total food loss.

Asia grows and consumes more than 50% of the world's vegetables, a category representing some 15% of total global loss. In fact, vegetables, fruit, dairy, seafood and meat represent greater than 50% of all food lost or wasted. These five categories have one thing in common - the life of this food can be extended with existing refrigeration technology.

Delhi is home to one of Asia's largest produce wholesale hubs. Every day dozens of trucks roll into the busy market at Azadpur Subzi Mandi. Each is full of produce waiting to be unloaded and repacked for local delivery.

Much of this activity is done in high humidity under a scorching sun, as Amy Kazmin writes in the FT. Some 40% of all fruit and produce that passes through this important hub will rot before it reaches consumers. Fresh green vegetables will last only two days at 30C or 86F.

The waste in Azadpur Subzi Mandi market is replicated across the country. Like many rapidly developing countries, India does not yet have an extensive cold chain. Of the 104 million metric tons of perishables transported among cities throughout India, only 4 million are transported in refrigerated vehicles and that's mostly for the transportation of milk.

Even saving a portion of what is wasted can have a dramatic impact on reducing hunger, poverty, political instability, water shortages and carbon emissions.

Food waste, climate emissions and water scarcity

Food waste represents 3.3 billion tonnes of embodied carbon dioxideemissions every year. That's the energy needed to produce the food we throw away: the gasoline for tractors, electricity for irrigation pumps, and the power to process harvests.

If we measured food waste as a country, it would be the third largest emitter of greenhouse gases behind the China and the US. This is stunning, especially when you consider that one in nine people don't have enough to eat.

And, if today's food system remains unchanged and global agriculture increases by 70% to satisfy global demand in 2050, greenhouse gas emissions could grow by 30%.

Beyond energy, water is a critical resource literally drained by food waste. Of all the water on the planet, just 1.3% is freshwater that we can drink. Of that, we use 70% to grow our food, but then we throw away more than one-third of our food.

Here's the stunning reality: the water we use to grow the food we throw away is greater than the water used by any single nation on the planet. Water lost by wasted food can even be measured at the micro level. For example, it takes approximately 20 litres or 5.4 gallons of water to grow a single head of broccoli.

The good news is that reducing food waste and loss will feed the hungry, address global warming and reduce demand on our natural resources. In better news, solutions are readily available for us to do so.

The chilling effect

Only 10% of perishable foods are refrigerated worldwide. A seamless cold chain would measurably reduce food waste. The cold chain is also becoming more energy-efficient, utilizing more environmentally sustainable technologies such as natural refrigerants.

Cold chain technology can also boost economies. According to the University of Nottingham, India produces 28% of the world's bananas representing just 0.3% of all international traded bananas.

With an upgraded cold chain infrastructure, the number of containers of bananas exported would grow from 3,000 to 190,000 - providing an additional 95,000 jobs and benefitting up to 34,600 small shareholder farmers.

But a growing and more advanced cold chain carries its own emission burden, posing the serious question: Will the climate emissions produced by more refrigerated trucks on the road counter the reduced emissions caused by food waste?

To answer that question we recently commissioned a study into the environmental impact of implementing advanced cold chain technologies in developing countries.

Going forward

If emerging economies adopted cold chain technologies to the level of developed countries, the reduction in greenhouse gas emissions from food waste would be nearly nine times the environmental impact of the expanded refrigerated transport and storage infrastructure.

Practical solutions must be supported by a greater global dialogue. The Global Food Cold Chain Council brings together technology providers, suppliers and retailers to green the cold chain, lower its carbon footprint and reduce food loss.

Similarly, efforts such as the inaugural World Cold Chain Summit to Reduce Food Waste last year in London convened economists, journalists and stakeholders in the cold chain industry to discuss strategies for preventing food loss and waste.

Governments also have an opportunity to create and enforce food safety standards. This will ensure proper transport and storage of perishable foods like meat, fish, and dairy, expanding the global food supply and reducing food waste-related environmental impacts.

We must all take responsibility. Let's buy the food we need so we throw away less. Let's accept that produce can be delicious if it is imperfect in appearance. Let's bring meals home that we don't finish in restaurants. Little changes in our behaviour will yield measurable results.

The way we systematically waste food in the face of the interelated challenges of rural poverty, global hunger and climate change is, meanwhile, one of humankind's unintended but most foolish practices.

The low-hanging fruit for climate protection is literally rotting. With support from existing technology, local governments and you and me, we can - and must - waste less and feed more.

"We wrote this book - with all proceeds going to food charities - to call attention to the extraordinary social and environmental opportunities created by wasting less food."

John Mandyck is the Chief Sustainability Officer for United Technologies Building & Industrial Systems, the world's largest provider of technologies and services dedicated to making buildings and cities more energy efficient, safe and secure, and the world's largest provider of food cold chain technologies. He also chairs the Corporate Advisory Board of the World Green Building Council, and serves as chairman of the Board of Directors for the Urban Green Council in New York. He was appointed by the US Secretary of Energy to co-chair the Department of Energy's Appliance Standards and Rulemaking Federal Advisory Committee.